feat: ollama tool shim (#1448)

Co-authored-by: Alice Hau <ahau@squareup.com>

crates/goose/src/agents/truncate.rs

@@ -19,6 +19,9 @@ use crate::message::{Message, ToolRequest};
 use crate::providers::base::Provider;
 use crate::providers::base::ProviderUsage;
 use crate::providers::errors::ProviderError;
+use crate::providers::toolshim::{
+    augment_message_with_tool_calls, modify_system_prompt_for_tool_json, OllamaInterpreter,
+};
 use crate::register_agent;
 use crate::session;
 use crate::token_counter::TokenCounter;
@@ -217,7 +220,17 @@ impl Agent for TruncateAgent {
             tools.push(list_resources_tool);
         }
 
-        let system_prompt = capabilities.get_system_prompt().await;
+        let config = capabilities.provider().get_model_config();
+        let mut system_prompt = capabilities.get_system_prompt().await;
+        let mut toolshim_tools = vec![];
+        if config.toolshim {
+            // If tool interpretation is enabled, modify the system prompt to instruct to return JSON tool requests
+            system_prompt = modify_system_prompt_for_tool_json(&system_prompt, &tools);
+            // make a copy of tools before empty
+            toolshim_tools = tools.clone();
+            // pass empty tools vector to provider completion since toolshim will handle tool calls instead
+            tools = vec![];
+        }
 
         // Set the user_message field in the span instead of creating a new event
         if let Some(content) = messages
@@ -236,7 +249,15 @@ impl Agent for TruncateAgent {
                     &messages,
                     &tools,
                 ).await {
-                    Ok((response, usage)) => {
+                    Ok((mut response, usage)) => {
+                        // Post-process / structure the response only if tool interpretation is enabled
+                        if config.toolshim {
+                            let interpreter = OllamaInterpreter::new()
+                                .map_err(|e| anyhow::anyhow!("Failed to create OllamaInterpreter: {}", e))?;
+
+                            response = augment_message_with_tool_calls(&interpreter, response, &toolshim_tools).await?;
+                        }
+
                         capabilities.record_usage(usage.clone()).await;
 
                         // record usage for the session in the session file